Storage management method and server

ABSTRACT

When the application I/O performance problem is solved, the I/O amount from the application is increased. In the conventional technique, no consideration has been taken on the affect of the increase of the application I/O performance to other applications. A resource whose I/O load is reduced by setting modification of a storage subsystem is specified and the application using this resource is specified as an application whose I/O processing amount may be increased. Furthermore, the resource used by the specified application and another application using this resource are specified as a resource and an application whose I/O processing performance may be lowered by the setting modification.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

Japan Priority Application JP-2006-055695, filed Mar. 2, 2006 includingthe specification, drawings, claims and abstract, is incorporated hereinby reference in its entirety. This application is a Continuation of U.S.application Ser. No. 12/893,718, filed Sep. 29, 2010, incorporatedherein by reference in its entirety, which is a Continuation of U.S.application Ser. No. 11/429,238, filed May 8, 2006, incorporated hereinby reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a performance analysis method in anenvironment having at least one server and at least one storagesubsystem.

As the storage capacity of each enterprise increases, more attention ispaid on the techniques to reduce the storage management cost. One ofsuch techniques is SAN (Storage Area Network). By using the SAN, asingle storage device is shared by a plurality of task servers so as tolocalize the storage operation task, thereby reducing the storageoperation management cost.

In a SAN environment, a single storage device is shared by a pluralityof task servers and accordingly, I/O from the servers are concentratedin the single storage. For this, a storage administrator shouldperiodically monitor the performance of the storage device so as toprevent an occurrence of a performance problem.

As a conventional technique for preventing the performance problem, forexample, there is a method for realizing I/O load control between diskdevices (for example, U.S. Pat. No. 6,446,161). In this method,according to the I/O load information in each disk device, data is movedfrom a disk device having a high I/O load to a disk device having a lowI/O load, thereby realizing the I/O load distribution.

SUMMARY OF THE INVENTION

When an application performance problem is caused by the I/O performancein a SAN environment, a position of the I/O bottleneck should beidentified and the storage setting should be modified. For example, whena performance problem is caused in a particular application by highloads of a disk device in the storage subsystem, a storage administratorallocates the I/O loads of the disk device to another disk device so asto reduce the loads of the disk device and solve the problem of theapplication I/O performance.

When the application I/O performance problem is solved, accesses fromthe application which has been suppressed by the high I/O loads arereleased and the I/O amount from the application is increased. However,as will be shown in a specific example below, it is known that such anincrease of the application I/O performance may affect anotherapplication. That is, this may affect another system such as an onlinetransaction system for which a high-speed I/O performance is required.

The affect of this problem will be explained in a specific example.

In the case of a database system requiring a high-speed response time,each time an update process is executed, user data is updated and a logfile is updated. When the user data and the log file are stored in asingle disk device, an I/O collision may occur and accordingly, they arenormally stored in separate disk devices. Suppose an I/O performanceproblem has occurred in a disk device storing the user data. As theamount of the updated user data is lowered, the amount of updated logfile acquired in synchronism with the updated user data is also lowered.Here, if the administrator improves the disk device performancecontaining the user data by the conventional technique, i.e., the I/Oload distribution due to data migration, I/O processes which have beensuppressed are released and accordingly, the amount of the updated logfile is also increased and the I/O loads on the disk device containingthe log file are also increased. Moreover, the I/O loads of resources orparts existing on the I/O path reaching the disk device are alsoincreased. By increase of the loads of the resources or the parts, theI/O performance of the other application using them is deteriorated anda new performance problem may be caused.

Thus, when the application I/O performance is deteriorated by thestorage subsystem as the bottleneck, setting of the storage subsystemshould be modified. However, the conventional method does not identifythe range of an affect to another application by solution of thebottleneck.

It is therefore an object of the present invention to grasp, in advance,an affect to the performance of the application, especiallydeterioration of the performance caused by storage subsystem settingmodification for reducing the I/O loads. More specifically, the objectof the present invention is to identify the application whose I/Operformance is improved by the storage setting modification by usingperformance of a server or a storage and the I/O path information fromthe application.

Another object of the present invention is to identify a resource whichexists on another path used by an application and whose I/O load may beincreased by the increase of the I/O amount of the application whose I/Operformance is improved.

Still another object of the present invention is to identify anapplication whose I/O performance may be deteriorated by the increase ofthe I/O amount from the application whose I/O performance is improved.

In a SAN environment including at least one storage subsystem and atleast one server, each server constituting the SAN environment has aserver information acquisition program for collecting information onapplications operating on the server, devices as I/O operation objectsof the applications, server side ports for SAN connection used by thedevices, and connection between storage side ports and logic volumes asserver side configuration information, and further collecting the CPUuse ratio of the server and the use ratio of each server side port asserver side performance information, and storing the collectedinformation in a storage management server.

The storage management server firstly acquires information on a storageside port, a cache, and RAID group used by each of the logical volumesas the storage side configuration information and further acquires theuse ratio concerning the logical volume, the storage side port, thecache, and the RAID group as the storage side performance information,and stores the acquired information in the storage management server.Furthermore, the storage management server displays a settingmodification definition view for defining the contents of the setting tobe modified for the storage subsystem and identifies the resource whoseI/O load is reduced by the modification of the setting according to thesetting contents set in the definition view and the acquiredconfiguration information. Furthermore, the storage management serveridentifies applications using the identified resource according to theconfiguration information and identifies, among the identifiedapplications, an application whose resource performance processingamount appearing on the path reaching the identified resource from theidentified application does not exceed a processing-enabled amount anddisplays it as an application whose I/O processing amount may beincreased. Thus, it is possible to identify an application whose I/Oprocessing amount may be increased by the storage setting modification.

Moreover, the storage management server acquires a resource used by theapplication whose I/O processing amount may be increased from theconfiguration information and specifies the acquired resource as aresource whose I/O processing performance may be lowered by the storagesetting modification.

Furthermore, the storage management server acquires another applicationusing the resource whose I/O processing performance may be lowered fromthe configuration information and specifies the acquired application asan application whose I/O processing performance may be lowered.

According to the present invention, it is possible to identify anapplication whose I/O amount may be increased by eliminating thebottleneck, and a resource and an application whose I/O performance maybe lowered by the increase of the I/O amount of the application.

Other objects, features and advantages of the invention will becomeapparent from the following description of the embodiments of theinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing system configuration of the presentembodiment.

FIG. 2 explains the I/O flow from an application to an external storagedevice in the embodiment.

FIG. 3 explains data flows between programs in the embodiment.

FIG. 4 explains a performance information table 201 in the embodiment.

FIG. 5 explains an I/O path information table 202 in the embodiment.

FIG. 6 explains a setting information input view 301 in the embodiment.

FIG. 7 explains an I/O amount increase application display view 302 inthe embodiment.

FIG. 8 explains an I/O performance lowering storage resource displayview 303 in the embodiment.

FIG. 9 explains an I/O performance lowering application display view 304in the embodiment.

FIG. 10 explains an I/O amount increase application search engine 111 inthe embodiment.

FIG. 11 explains an I/O performance lowering storage resource searchengine 112 and an I/O performance lowering application search engine 113in the embodiment.

FIG. 12 shows an example of the SAN environment in the embodiment.

FIG. 13 is a specific resource list for identifying a resource whoseperformance is improved.

FIG. 14 shows relationships between the search engines and theprocesses.

DESCRIPTION OF THE EMBODIMENTS

A storage management system in the embodiment below is simplified ascompared to an ordinary storage management system for simplifying theexplanation. However, the scope of invention is not to be limited to theembodiment.

Description will now be directed to a first embodiment of the presentinvention.

(1) System Configuration

Firstly, referring to FIG. 1, explanation will be given on the systemconfiguration of the present embodiment.

The system includes a plurality of storage subsystems 020, a pluralityof servers 001, a management server 004, a LAN (Local Area Network) 003connecting these components from one to another, and a SAN 002connecting the storage subsystems 020 to the servers 001. In FIG. 1, forsimplification, only one storage subsystem 020 and only one server 001are shown. It should be noted that the LAN is connected to thecomponents via respective LAN connection ports 017. Moreover, the SAN002 is connected to the components via ports 023 and 024.

The server 001 includes a CPU 011, a memory 015, an external storagedevice 016, a LAN connection port 017, and a server side port 023. Themanagement server 004 includes a CPU 011, a display device 012, a keyadapter (keyboard) 013, a mouse 014, a memory 015, an external storagedevice 016, and a LAN connection port 017. In each server 001, a serverinformation acquisition program 100 is executed. It should be noted thatthe server information acquisition program 100 is a program foracquiring operation information on the server 001. This will be detailedlater.

Furthermore, in the management server 004, a storage performanceanalysis program 110 is executed. Moreover, information required forexecuting the storage performance analysis program 110 is held in a datastorage area 200 in the external storage device 016. The storageperformance analysis program 110 is a program for specifying the rangeof the affect to the application and the storage subsystem 020 by thestorage configuration modification. This will be detailed later.

The storage subsystem 0202 is an apparatus including at least oneexternal storage device 016, at least one LAN connection port 017, atleast one cache memory (hereinafter, referred to as a cache) 021, amicro-program 022, and at least one storage side port 024.

It should be noted that the storage side port 024 reads data from thecache 021 or the external storage device 016 and writes data into thecache 021 or the external storage device 016 according to an I/O commandsent from the server side port 023.

Moreover, the micro-program has a function for acquiring performanceinformation on the external storage device 016, the cache 021, and thestorage side port 024 and a function for modifying the setting of thestorage configuration. More specifically, the micro-program 022 has afunction constituting a RAID (Redundant Array of Inexpensive Disks)group having a RAID level specified by a plurality of external storagedevices 016 and a function for creating a volume having a specifiedcapacity from the RAID group. It should be noted that a volume createdin the storage subsystem will be expressed as a logical volume.Moreover, the micro-program 022 also has a function to move a logicalvolume to another RAID group. Moreover, the micro-program 022 has afunction for making data in a particular logical volume resident in thecache 021. Furthermore, the micro-program 022 has a function forsuppressing the I/O amount from the particular server 001 or a device032 shown in FIG. 2 for the particular storage side port 024 to apredetermined amount.

(2) I/O Flow

Next, explanation will be given on connection relationship between anapplication program (hereinafter, referred to simply as an application)and a storage subsystem with reference to FIG. 2. The micro-program 022builds a RAID group 033 having a particular RAID level by a plurality ofexternal storage devices 016. Moreover, the micro-program 022 creates alogical volume 034 having a specified capacity from the RAID group 033.The created logical volume 034 is recognized in the server 001, as adevice 032 to which a file system 031 accesses via the storage side port024 and the server side port 023. That is, device 016 is the targetresource of the I/O operation when viewed from the file system 031, andone of resources on the path which I/O issues when viewed from aresource of the server side port 023 et seq. For example, the device 032is a device driver for controlling a peripheral device. An OS (OperatingSystem) on the server 001 creates a file having a particular size by thefile system 031 according to a request from the application 030.

The I/O issued by the application 030 is sent to the storage side port024 via the file system 031, the device 032, and the server side port023. When a data acquisition I/O is sent to the storage side port 024and the requested data is present in the cache 021, the data isreturned. If the data is not present in the cache 021, data is acquiredfrom the logical volume 034 used by the application 030. When a datawrite I/O is sent to the storage side port 024, data is written into thecache 021 and write completion is reported to the server 001.Furthermore, the requested data in the cache 021 is written into thelogical volume 0334 used by the application 030.

It should be noted that for simplifying the explanation below, thedevice 032, the server side port 023, the storage side port 024, thecache 021, the logical volume 034, and the RAID group 033 will be called“resources” as a whole.

(3) Relationship between Programs

Referring to FIG. 3, explanation will be given on the relationshipbetween a server information acquisition program 100 operating in theserver 001, a micro-program 022 operating in the storage subsystem 020,and a storage performance analysis program 110 operating in themanagement server 004.

The server information acquisition program 100 periodically acquiresperformance information on the server 001 and the I/O path informationand stores the acquired information in a data storage area 200. Itshould be noted that the data storage area 200 is formed by aperformance information table 201 holding performance information and anI/O path information table 202 holding the I/O path information.

More specifically, the server information acquisition program 100acquires performance information on the CPU 011 in the server 001, thedevice 032, and the server side port 023 and stores the information inthe performance information table 201. The performance information canbe acquired by using a system call provided by the OS. Moreover, theserver information acquisition program 100 acquires information on thefile system 031 used by the application 030 and information on thedevice 032 used by the file system 031, the server side port 023 used bythe device 032, and the logical volume 034 and stores these informationin the I/O path information table 202. The relationship between theapplication 030 and the file system 031 can be acquired, for example,from API (Application Program Interface) provided by the application030. Moreover, the relationship between the file system 031 and thedevice 032 can be acquired, for example, by using the OS system call.Furthermore, the relationship between the device 032, the server sideport 023, and the logical volume 034 can be acquired, for example, byusing an inquiry command of a SCSI (Small Computer System Interface).

As shown in FIG. 3, the storage performance analysis program 110 isformed by a storage information acquisition engine 101, an I/O amountincrease application search engine 111, an I/O performance loweringstorage resource search engine 112, and an I/O performance loweringapplication search engine 113.

The storage information acquisition engine 101 is a program forperiodically acquiring performance information and configurationinformation on various devices in the storage subsystem 020 and storingthe acquired information in the performance information table 201 andthe I/O path information table 202.

The I/O amount increase application search engine 111 is a subprogramfor acquiring setting modification for reducing the I/O load to beexecuted for the storage subsystem 020 by the storage administrator andidentifying an application whose I/O amount may be increased by thesetting modification. The I/O amount increase application search engine111 displays a setting information input view 301 for inputting thesetting modification, identifies an application whose I/O amount may beincreased by using the contents set in the setting information inputview 301, the performance information table 201, and the I/O pathinformation table 202, and displays the identified result on the I/Oamount increase application table view 302. This will be detailed later.

The I/O performance lowering storage resource search engine 112 is aprogram for identifying a resource in the storage whose I/O load may beincreased by the setting modification specified on the settinginformation input view 301 and the I/O amount increase from theapplication 030 displayed on the I/O amount increase application displayview 302. According to the output result of the I/O amount increaseapplication search engine 111 and the data in the I/O path informationtable 202, the I/O performance lowering storage resource search engine112 identifies a resource in the storage whose I/O performance may belowered and outputs it to the I/O performance lowering storage resourcedisplay view 303. This will be detailed later.

The I/O performance lowering application search engine 113 is a programfor identifying an application 030 whose I/O performance may be loweredby the increase of the I/O amount from the resource displayed on the I/Operformance lowering storage resource display view 303. According to theoutput result of the I/O performance lowering storage resource searchengine 112 and the data in the I/O path information table 202, the I/Operformance lowering application search engine 113 identifies anapplication whose I/O performance may be lowered and outputs it to theI/O performance lowering application display view 304. This will bedetailed later.

Referring to FIG. 14, explanation will be given on outline of theprocesses performed by the search engines 111, 112, and 113 and therelationship with the object to be processed. The arrows shown by solidbroken lines in FIG. 14 indicate processes for extracting a particularresource and application contained in the path by searching the I/O pathinformation table 202.

An application AP1 uses a logical volume VOL 1 via a path 1 and anapplication AP2 uses a logical volume VOL 2 via a path 2-1 and a logicalvolume VOL 3 via a path 2-2. The logical volume VOL 1 and VOL 2 belongto the same RAID group. An application AP3 uses a logical volume VOL 4via a path 3 and some of the resources on the path 3 are common to thepath 2-2. Hereinafter, it is assumed that the I/O load is reduced forthe logical volume VOL 2 used by the application AP2.

[1] When setting modification (such as movement of a logical volume) forreducing the I/O load for the logical volume VOL 2 is performed, the I/Oamount increase application search engine 111 searches the I/O path(path 2-1) from VOL 2 to the application AP2 and the I/O path (path 1)from the logical volume VOL 1 sharing the RAID group with VOL 2 to theapplication AP1 according to the I/O path information table 202 andidentifies an application (AP2 in the figure) connected to the pathcontaining a resource whose I/O amount may be increased among theresources on the I/O path according to the performance information table201. As for the application AP1, suppose that the I/O amount of at leastone resource contained on the I/O path (path 1) connected to the AP1 hasalready (before setting modification) reached the upper limit accordingto the performance information table 201. As a result, the applicationAPI judges that the possibility of increase of the I/O amount is loweven if setting modification is performed so as to reduce the I/O loadfor the logical volume VOL 2.

[2] The I/O performance lowering storage resource search engine 112searches another path (path 2-2) connected to the identified I/O amountincrease application (AP2) according to the I/O path information table202, thereby identifying a resource on a path (path 2-2) whose I/Operformance may be lowered by increase of the I/O amount of the I/Oamount increase application (AP2).

[3] The I/O path performance application search engine 113 searchesfurther another path (path 3) commonly containing the resourceidentified by [2] according to the I/O information table 202 andidentifies the application (AP3) connected to the searched path as anI/O performance lowering application. That is, the application connectedto still another path (path 3) sharing some of the resources on theother path (path 2-2) containing a resource whose I/O performance may belowered by the I/O amount increase of the I/O amount increaseapplication is identified as an application whose I/O performance may belowered.

(4) Data Storage Area

Explanation will be given on a data storage area according to anembodiment of the present invention. Tables explained below arecontained in a data storage area 200 in the external storage device 016of the management server 004.

Firstly, referring to FIG. 4, explanation will be given on a performanceinformation table 201. The performance information table 201 has columnsas follows: a resource name 501, a performance type 502, a performancevalue 503, and a data collection time 504. The server informationacquisition program 100 and the storage information acquisition engine101 acquire various performances of the server 001 or the storagesubsystem 020 and add the acquired information as a record to theperformance information table 201.

For example, the server information acquisition program 100 periodicallyacquires the use ratio of the CPU 011 and stores “CPU (server 1)” in theresource name 501, “CPU use ratio” in the performance ratio 502, theacquired performance value in the performance value 503, and the dataacquisition time in the data acquisition time 504. These information areconfigured as a single record. Moreover, the server informationacquisition program 100 can also store the use ratio of the server sideport 023 similarly in the performance information table. Moreover, thestorage information acquisition engine 101, similarly, periodically canacquire the use ratio of the storage side port 0224, the use ratio ofthe cache 021, and the use ratio of the RAID group 033 and store theacquired information as a record in the performance information table201.

Next, referring to FIG. 5, explanation will be given on an I/O pathinformation table 202. The I/O path information table 202 has followingcolumns: an application name 401, a server name 409, a device name 402,a server side port name 403, a storage name 404, a storage side portname 405, a RAID group name 406, a cache name 407, and a logical volumename 408. The table shows configuration of a plurality of resources onthe path and connection relationships between resources. The serverinformation acquisition program 100 and the storage informationacquisition engine 101 acquire configuration information on the server001 or the storage subsystem 020 and add the acquired information as arecord to the I/O path information table 202.

For example, the server information acquisition program 100 acquires thename of the application 030 and the device 032 used by the application030 by the API provided by the application 030 and stores the acquiredinformation in the application name 401 and the device name 402,respectively. Moreover, the server name is acquired from the server 001and the acquired information is stored in the server name 409.Furthermore, the server information acquisition program 100 executes theinquiry command of SCSI to each device registered in the device name 402so as to acquire the server side port 023 used by the device 032, thestorage 020, the storage side port 0224, and the name of logical volume034 and registers the acquired information in the respective columns.Moreover, the storage information acquisition engine 101 acquires theRAID group 033 used by the logical volume 034 and the name of the cache021 from the micro program 022 for each of logical volumes 034 containedin the I/O path information table 202 and registers the acquiredinformation in the respective columns.

(5) Explanation of Views

Next, referring to FIG. 6 to FIG. 9, detailed explanation will be givenon each of the views displayed on the display device 012 of themanagement server 004 by the storage performance analysis program 110.

(5-1) Setting Information Input View 301

FIG. 6 shows an example of a setting information input view 301according to the present embodiment. The setting information input view301 is plotted by the I/O amount increase application search engine 111for receiving information on the operation set for the storage subsystem020 to be executed by the storage administrator. Moreover, the settinginformation input view 301 is formed by a resource selection area 610and an operation setting area 620. The I/O amount increase applicationsearch engine 111 displays a list of object resources whose setting isto be modified in the resource selection area 610. For example, thestorage side port 024, the cache 021, and the logical volume 034contained in the I/O path information table 202 are displayed. Moreover,the I/O amount increase application search engine 111 displays a list622 of resources associated with an operation list 621 of the operationsassociated with the resources selected in the resource selection area610.

Correspondence relationships between the contents displayed in theresource selection area 610, the operation list 621, and the resourcelist 622 are stored in a table shown in FIG. 13 which will be detailedlater.

For example, if the storage side port 024 is selected from the objectresource list in the resource selection area 610, the I/O amountincrease application search engine 111 displays “I/O amount suppressionfrom a particular device” and “I/O amount priority from a particulardevice” as the operation list 621. Furthermore, the I/O amount increaseapplication search engine 111 displays a list of devices using thestorage side port 024 specified in the resource selection area 610, inthe resource list 622. It should be noted that information in theresource list 622 may be searched from the information in the I/O pathinformation table 202.

Moreover, if the cache 021 is selected from the object resources in theresource selection area 610, the I/O amount increase application searchengine 111 displays “setting a particular logical volume to a residentstate” and “release of the resident state of a particular logicalvolume” as the operation list 621. Furthermore, the I/O amount increaseapplication search engine 111 displays a list of logical volume 034using the cache 021 specified in the resource selection area 610, in theresource list 622. It should be noted that the information in theresource list 622 may be searched from the information in the I/O pathinformation table 202.

Moreover, if the logical volume 034 is selected from the objectresources in the resource selection area 610, the I/O amount increaseapplication search engine 111 displays “used port modification”, “usedcache modification”, and “used RAID group modification” as an operationlist 621. Furthermore, when “used port modification” is selected in theoperation list 621, the I/O amount increase application search engine111 displays a port list in the resource list 622. Moreover, when “usedcache modification” is selected in the operation list 621, a cache listis displayed on the resource list 622. Moreover, when “used RAID groupmodification” is selected on the operation list 621, a RAID group listis displayed on the resource list 622. Information in these resourcelists 622 may be searched from the information in the I/O pathinformation table 202.

(5-2) I/O Amount Increase Application Display View 302

FIG. 7 shows an example of the I/O amount increase application displayview 302 according the present embodiment. The I/O amount increaseapplication display view 302 is plotted by the I/O amount increaseapplication search engine and outputs the output result of the I/Oamount increase application search engine 111.

As shown in FIG. 7, the I/O amount increase application display view 302is formed by an application list display table 700. The application listdisplay table 700 has following columns: an application name 701, I/Oprediction amount after modification 702, and remarks 703. The displaycontents of the columns 702 and 703 of the table 700 shown in FIG. 7 areobtained from the performance information table 201 and the executionresult of the I/O amount increase application search engine 111.

(5-3) I/O Performance Lowering Storage Display View 303

FIG. 8 shows an example of the I/O performance lowering storage displayview 303 in the present embodiment. The I/O performance lowering storagedisplay view 303 is plotted by the I/O performance lowering storageresource search engine 112 and outputs the output result of the I/Operformance lowering storage resource search engine 112.

As shown in FIG. 8, the I/O performance lowering storage display view303 is formed by an I/O performance lowering storage resource list table800. The I/O performance lowering storage resource list table 800 hasfollowing columns: a resource name 801 and a lowering condition 802. Thedisplay contents of the column 802 of the table 800 shown in FIG. 8 canbe obtained from the execution result of the I/O performance loweringstorage resource search engine 112.

(5-4) I/O Performance Lowering Application Display View 304

FIG. 9 shows an example of the I/O performance lowering applicationdisplay view 304 in the present embodiment. The I/O performance loweringapplication display view 304 is plotted by the I/O performance loweringapplication search engine 113 and outputs the output result of the I/Operformance lowering application search engine 113.

As shown in FIG. 9, the I/O performance lowering application displayview 304 is formed by a performance deterioration list table 900. Theperformance deterioration application list table 900 has followingcolumns: an application name 901, a cause 902, a generation condition903, and a countermeasure plan 904. The display contents of the column902 of the table 900 shown in FIG. 9 can be obtained from the executionresult of the I/O performance lowering application search engine 113.The display contents of the column 903 of the table 900 shown in FIG. 9can be obtained from the execution result of the I/O performancelowering storage resource search engine 112 like the column 802 of FIG.8. Furthermore, a IF-THEN type rule having the display contents of thecolumns 902 and 903 in the preamble and the display contents of thecolumn 904 in the conclusion is stored in a rule table in advance sothat the display contents of the column 904 are displayed by using therule table.

(6) Storage Performance Analysis Program Details

Next, detailed explanation will be given on the I/O amount increaseapplication search engine 111, the I/O performance lowering storageresource search engine 112, and the I/O performance lowering applicationsearch engine 113.

(6-1) I/O Amount Increase Application Search Engine 111

Firstly, FIG. 10 shows an example of the I/O amount increase applicationsearch engine 111.

The I/O amount increase application search engine 111 firstly displays asetting information input view 301 (step 1001).

Next, according to the information inputted by the setting informationinput view 301, a resource whose performance is improved is identified(step 1002). FIG. 13 shows a list 1300 of resources whose performance isimproved. The list 1300 shown in FIG. 13 is stored in the data storagearea 200 in the external storage device 016 of the management server004. The list 1300 has following columns: a case 1301, a resourceselection 1302, an operation list 1303, a resource list 1304, and aperformance improvement resource 1305. The columns 1302, 1303 and 1304correspond to the contents displayed in the areas 610, 621 and 622 ofFIG. 6, respectively.

Contents of FIG. 13 are as follows. When operations shown in theoperation list 621 are executed for the resources shown in the resourceselection 610, the I/O amount is modified from the associated resourcesshown in the resource list 622 to the resources shown in the resourcelist 610 in the case of (a) to (d) and the I/O load of the associatedresources shown in the resource list 622 is reduced in the case if (e)to (g).

This step identifies a resource whose performance is improved accordingto the list shown in FIG. 13. More specifically, a resource isidentified as follows.

(a) Case when the storage side port 024 is selected in the resourceselection area 610 and “I/O amount priority from a particular device” isselected in the operation list 621:

In this case, the I/O request to the storage side port 024 selected inthe resource selection area 610 from the device 032 selected in theresource list 622 has a higher priority. Accordingly, the responseperformance of the I/O issued to the selected storage side port 024 fromthe device 032 is normally improved. The I/O amount increase applicationsearch engine 111 acquires the device 032 selected in the resource list622 and specifies the acquired device 032 as a resource whose I/Operformance is improved.

(b) Case when the storage side port 024 is selected in the resourceselection area 610 and “I/O amount suppression from a particular device”is selected in the operation list 621:

In this case, the I/O request to the storage side port 024 selected inthe resource selection area 610 from the device 032 selected in theresource list 622 is suppressed. Accordingly, the load of the selectedstorage side port 024 is reduced and the performance of the selectedstorage side port 024 is normally improved. The I/O amount increaseapplication search engine 111 acquires the storage side port 024selected in the resource selection area 610 and specifies the acquiredstorage side port 024 as a resource whose I/O performance is improved.

(c) Case when the cache 021 is selected in the resource selection area610 and “setting a particular volume to a resident state” is selected inthe operation list 621:

In this case, data in the logical volume 034 selected in the resourcelist 622 is resident in the cache 021 and the I/O response performanceof the selected logical volume 034 is normally improved. The I/O amountincrease application search engine 111 acquires the logical volume 034selected in the list 622 and specifies the acquired logical volume 034as a resource whose I/O performance is improved.

(d) Case when the cache 021 is selected in the resource selection area610 and “release of a particular volume from the resident state” isselected in the operation list 621:

In this case, the area of the cache 021 used by the logical volume 034is released and accordingly, the performance of the cache 021 which hasbeen used is improved. The I/O amount increase application search engine111 acquires the cache 021 selected in the resource selection area 610and specifies the acquired cache 021 as a resource whose I/O performanceis improved.

(e) Case when the logical volume 034 is selected in the resourceselection area 610 and “used port modification” is selected in theoperation list 621:

In this case, the load on the storage side port 024 selected in theresource list 622 from the logical volume 034 selected in the resourceselection area 610 is reduced. Accordingly, the load on the selectedstorage side port 024 is normally reduced. The I/O amount increaseapplication search engine 111 acquires the storage side port 024selected in the resource list 622 and specifies the acquired storageside port 024 as a resource whose I/O performance is improved.

(f) Case when the logical volume 034 is selected in the resourceselection area 610 and “used cache modification” is selected in theoperation list 621:

In this case, the load on the cache 021 selected in the resource list622 from the logical volume 034 selected in the resource selection area610 is reduced. Accordingly, the load on the selected storage side cache021 is normally reduced. The I/O amount increase application searchengine 111 acquires the storage side cache 021 selected in the resourcelist 622 and specifies the acquired cache 021 as a resource whose I/Operformance is improved.

(g) Case when the logical volume 034 is selected in the resourceselection area 610 and “used RAID group modification” is selected in theoperation list 621:

In this case, the load on the RAID group 033 selected in the resourcelist 622 from the logical volume 034 selected in the resource selectionarea 610 is reduced. Accordingly, the load on the selected RAID group033 is normally reduced. The I/O amount increase application searchengine 111 acquires the RAID group 033 selected in the resource list 622and specifies the acquired RAID group 033 as a resource whose I/Operformance is improved.

Furthermore, the I/O amount increase application search engine 111searches for an application 030 containing a resource which has beenspecified in step 1002 as a resource whose performance is improved inthe I/O path, from the I/O path information table 202 (step 1003). Forexample, when the resource specified in step 1002 is a RAID group 033, arecord having the name of the RAID group 033 in the RAID group name 406is searched from the I/O path table 202, thereby specifying anapplication.

It should be noted that in this step some applications are excludedaccording to the contents specified in the operation setting area 620.More specifically, when “suppression of I/O amount from a particulardevice” or “release of the resident state of a particular logicalvolume” is selected, it is clear that the application performance willnot be improved and the application using the device 032 or the logicalvolume 034 selected in the resource list 622 is excluded. Moreover, whenthe logical volume 034 is selected in the resource selection area 610,the application 030 using the logical volume 034 is excluded. Theapplication 030 to be excluded can be searched from the I/O pathinformation table 202.

Furthermore, the I/O amount increase application search engine 111checks (step 1004) whether the process of step 1005 et seq. have beenperformed for the application 030 acquired in step 1003. If theprocesses have been executed for all the searched applications 030, theprocessing is terminated. Otherwise, one of the applications 030 isselected from the application list acquired in step 1003 and control ispassed to step 1005.

Next, the I/O amount increase application search engine 111 searches(step 1005) for resources appearing on the I/O path from the application030 selected in step 1004 to the resource selected in step 1002. Itshould be noted that the resource on the I/O path can be acquired fromthe I/O path information table 202. More specifically, a record havingthe application 030 selected in step 1004 and the resource acquired instep 1002 as values is searched from the I/O path information table 202,thereby acquiring the resource on the I/O path.

Moreover, the I/O amount increase application search engine 111 acquiresperformance information for each of the resources acquired in step 1005,from the performance information table 201 (step 1006).

Furthermore, the I/O amount increase application search engine 111checks whether the performance information acquired in step 1006includes a resource exceeding the upper limit of the processing. If sucha resource exists, control is passed to step 1008. Otherwise, control ispassed to step 1009 (step 1007).

It should be noted that the processing upper limit can be checked, forexample, by checking the I/O processing time per unit time. For example,when the CPU use ratio or resource use ratio is 100%, it is judged thatthe server having the CPU or the resource has reached the processingupper limit. Moreover, the I/O amount increase application search engine111 displays a view for setting the processing upper limit and can judgewhether the processing upper limit is reached, by using the set value.

Furthermore, when the function provided by the micro-program 022 tosuppress the I/O amount from a particular device 032 for a particularstorage side port 024 is used or when the I/O amount from the device 032for the storage side port 024 exceeds a predetermined amount, it ispossible to assume that the storage side port 024 has reached theprocessing upper limit. It should be noted that the setting informationmay be acquired, for example, from the micro-program 022.

In step 1008, the application 030 selected in step 1004 is displayed asan application 0303 which cannot increase the I/O amount in the I/Oamount increase application display view 302. Moreover, the performancetype which disabled I/O increase is also displayed. Thus, it is possibleto grasp the application 030 whose I/O performance is not improved evenif the modification set in the setting information input view 301 ismodified. Furthermore, by displaying not only the application 030 butalso the performance type disabling the I/O amount increase, it ispossible to know which performance information is the performancebottleneck and which performance information should be improved toimprove the I/O performance of the application 030. For example, whenthe server CPU use ratio is the cause, an unnecessary service is stoppedand the CPU is intensified so as to improve the performance.

In step 1009, the application selected in step 1004 is displayed as theapplication 030 whose I/O amount can be increased on the I/O amountincrease application display view 302. Thus, it is possible to grasp theapplication 030 whose I/O performance may be improved by themodification set in the setting information input view 301. Furthermore,by displaying the grasped applications 030 in a list, it is possible toconfirm that the I/O performance of the application 030 not requiring ahigh-speed I/O performance such as a test application is not improved.

(6-2) I/O Performance Lowering Storage Resource Search Engine 112

FIG. 11 shows an I/O performance lowering storage resource search engine112 according to an embodiment.

Firstly, the I/O performance lowering storage resource search engine 112specifies a resource used by the application 030 whose I/O amount may beincreased according to the I/O path information table 202, from theapplications 030 which are displayed on the I/O amount increaseapplication display view 302 as applications whose I/O amount may beincreased (step 1101). For example, a record having the application 030displayed on the I/O amount increase application display view 302 asapplications whose I/O amount may be increased is searched from the I/Opath information table 202 and by referencing the storage side port name405, the RAID group name 406, the cache name 407, and the logical volumename 408 from the searched record, it is possible to acquire a list ofresources used by the application 030 whose I/O amount may be increased.

Next, the I/O performance lowering storage resource search engine 112displays the resource acquired in step 1101 on the I/O performancelowering storage resource display view 303 (step 1102). Thus, it ispossible to grasp the range of affect of the storage settingmodification to the resource in the storage.

In general, when the I/O performance of the storage side port 024, thecache 021, the RAID group 033 is deteriorated by execution of a plentyof I/O commands issued to a particular device 032, it is effective tosuppress the I/O amount between the device 032 and the storage side port024 used by the device 032. By using this method, it is possible tosolve the problem of the performance of the storage side port 024, thecache 021, or the RAID group 033.

According to the present embodiment, as shown in FIG. 8, the application030 whose I/O amount may be increased by the setting modification of thestorage subsystem 020 and the storage side port 024 used by theapplication are displayed at the lowering condition 802 and the resourceused by the application whose I/O amount may be increased is displayedat the resource name 801. Accordingly, the storage administrator canjudge a method to prevent an affect of the application 030 whose I/Oamount is increased by the setting modification of the storage subsystem020. It should be noted that the information for judging the affect canbe acquired by fetching the application name 401 and the storage sideport name 405 from the record acquired in step 1101.

For example, suppose that setting modification of the storage subsystem020 is found to increase the I/O amount from the application 020(application A) requiring a high-speed I/O performance such as a DBserver and an application 020 (application B) not requiring a high-speedI/O performance such as a test server. In this case, the I/O amount fromthe application B is limited at the storage side port 024, so as toprevent the affect by the I/O amount increase of the application B.

(6-3) I/O Performance Lowering Application Search Engine 113

FIG. 11 shows an I/O performance lowering application search engine 113according to an embodiment.

Firstly, the I/O performance lowering application search engine 113searches for the application 030 including the resource searched in step1101 in the I/O path from the I/O path information table 202 (step1103). For example, the I/O performance lowering application searchengine 113 searches for a record having the resource specified in step1101 and contained in one of the storage side port name 405, the RAIDgroup name 406, the cache name 407, and the logical volume name 408,from the I/O path information table 202 and acquires the applicationname 401 contained in the searched record.

Step 1103 specifies the application connected to another path commonlyincluding the I/O performance lowering resource contained in the pathused by the I/O amount increase application, as the I/O performancelowering application.

Next, the I/O performance lowering application search engine 113displays the application 030 acquired in step 1103 on an I/O performancelowering application display view 304 (step 1104). Thus, it is possibleto grasp the range of affect of the storage setting modification to theapplication 030.

Moreover, as shown in FIG. 9, the resource specified in step 1101 can bedisplayed in the cause 902 as a resource causing lowering of the I/Operformance of the application 030 specified in step 1103. Thus, theapplication 030 whose I/O performance may be lowered by the storagemodification is displayed in the application name 901, and the resourceas the cause is displayed in the cause 902, thereby specifying aresource to be monitored after the storage setting modification.Moreover, by setting the relationship between the cause of the I/Operformance lowering and its countermeasure in advance, it is possibleto indicate a countermeasure candidate for preventing the I/O resourceperformance lowering of the resource displayed in the cause 902 as shownin the countermeasure candidate in FIG. 9.

For example, when the storage side port 024 causes the I/O performancelowering of the application 030 whose I/O performance may be lowered, itis possible to prevent the I/O performance lowering of the applicationor reduce the degree of the affect by “setting a higher priority to theI/O amount from the application 030”. Moreover, when the cache 021causes the I/O performance lowering of the application 030, it ispossible to prevent the I/O performance lowering of the application 030or reduce the degree of the affect by “setting the logical volume usedby the application 0303 to a state resident in the cache 021”. It shouldbe noted that the logical volume used by the application 030 can beacquired by referencing the logical volume name 408 contained in the I/Opath information table 202. Furthermore, when the RAID group 033 causesthe I/O performance lowering of the application 030, it is possible toprevent the I/O lowering of the application 030 or reduce the degree ofthe affect by “reducing the load on the RAID group 033”.

By using the aforementioned methods, it is possible to judge which ofthe methods is to be used to eliminate affect by the application 030which can increase the I/O amount by the setting modification of thestorage subsystem 020. For example, suppose that the I/O amounts fromthe application (application A) requiring a high-speed I/O performancesuch as a DB server and an application (application B) not requiring ahigh-speed I/O performance such as a test server are to be increased. Inthis case, by limiting the I/O amount from the application B at thestorage side port 024, it is possible to eliminate the affect by the I/Oamount increase of the application B.

(7) Specific Examples

Referring to a specific example shown in FIG. 12, explanation will begiven on the outline of the present processing. It should be noted thatto simplify the explanation, explanation on the cache 021, the filesystem 031, and the device 032 is omitted. The I/O path informationtable 202 corresponding to the system configuration shown in FIG. 12 isshown in FIG. 5.

Suppose that the logical volume 034f used by the application 030f ismoved from the RAID group 033a to the RAID group 033d. Here, the I/Oamount increase application search engine 111 firstly identify aresource whose performance is improved by the method shown in step 1002.In the case shown in FIG. 12, the logical volume 034f is moved toanother RAID group 033d and it is judged that the load of the RAID group033a is reduced.

Next, by using the method shown in step 1003, the I/O amount increaseapplication search engine 111 specifies the application 030 using theRAID group 033a. More specifically, the I/O amount increase applicationsearch engine 111 searches for a record having the RAID group 033a inthe RAID group name 406 from the I/O pass information table 202 andchecks the application name 401 contained in the searched record. Thisspecifies the application 030a and the application 030b as theapplication 030 whose I/O may be increased.

Furthermore, by using the method shown in steps 1005 and 1006, the I/Oamount increase application search engine 111 acquires the resource usedby the application 030 and performance information on each resource andlastly, according to the acquired performance information, judgeswhether the I/O amount of the application 030a and 030b may be increasedby the method shown in step 1007.

In the case shown in FIG. 12, for example, the application 030b isspecified as the application whose I/O may be increased according to aprocedure as follows. Firstly, a record having the application 030a andthe application 030b in the application name 401 is searched from theI/O path information table 202. Next, from the searched record, theserver name 409, the server side port name 403, the storage side portname 405, and the RAID group name 406 are acquired. In this case, aserver 001a and a server 001b are acquired as the server 001; a serverside port 023a and a server side port 023b are acquired as the serverside port 0223; a storage side port 024a and a storage side port 024bare acquired as the storage side port 024; and a RAID group 033a isacquired as the RAID group 033.

Next, performance of the acquired resource is acquired from theperformance information table 201 and it is judged whether the I/Oamount of the application 030a and 030b may be increased. For example,when the CPU use ratio of the server 001a or the use ratio of the serverside port 023a is 100%, the I/O amount from the application 030aoperating in the server 001a to the RAID group 033 a will not beincreased. Accordingly, the application 030a is specified as theapplication whose I/O amount will not be increased. Moreover, when theuse ratios of the server 001b, the server side port 0234b, and thestorage side port 024b are all below 100%, the application 030b usingthe ports 023b, 024b is specified as the application whose I/O amountmay be increased.

Next, according to the method shown in step 1101, the I/O performancelowering storage resource search engine 112 specifies a resource whoseI/O load is increased by the I/O amount increase of the application030b. In the example shown in FIG. 12, for example, according to aprocedure shown below, the server side port 023b, the server side port023c, the storage side port 024b, the storage side port 024c, the RAIDgroup 033a, and the RAID group 033b are specified as the resources whoseI/O load may be increased. Firstly, a record having the application 030bfor the application name 401 is searched from the I/O path informationtable 202. Next, from the searched record, the server side port name403, the storage side port name 405, and the RAID group name 406 areacquired. Thus, it is possible to acquire the server side port 023b, theserver side port 023c, the storage side port 024b, the storage side port024c, the RAID group 033a, and the RAID group 033b. Moreover, the I/Operformance lowering storage resource search engine 112 specifies theacquired resource as the resource whose I/O performance may be lowered.

Lastly, the I/O performance lowering application search engine 113specifies an application having the resource specified by the I/Operformance lowering storage resource search engine 112 in the I/O pathaccording to step 1103. In the example shown in FIG. 12, according to aprocedure explained below, the application 030a and the application 030care specified as the application 030 whose I/O performance may bedeteriorated by the setting modification of the storage subsystem 020.Firstly, the I/O performance lowering application search engine 113searches for a record having the server side port 023c for the serverside port name 403 or a record having the storage side port 024b or thestorage side port 024c for the storage side port name 405 or a recordhaving the RAID group 033a or the RAID group 033b for the RAID groupname 406 from the I/O path information table 202 and acquires theapplication name 401 of the searched record. In this case, it ispossible to acquire the application 030a using the RAID group 033a andthe application 030c using the storage side port 024c. The I/Operformance lowering application search engine 113 specifies theapplications 030a and 030c as the application 030 whose I/O performancemay be lowered.

(8) Other Embodiments

According to the present embodiment, it is possible to identify theapplication 030 whose I/O amount may be increased by eliminating thebottleneck and a resource and the application 030 whose I/O performancemay be lowered by the I/O amount increase of the application 030 whenperforming setting modification of the storage subsystem 020.

It should be noted that the setting information input view 301 in theaforementioned embodiment may be extended and a plurality of settingcontents may be inputted. By simultaneously inputting a plurality ofsetting contents, for example, it is possible to identify the range ofaffect to another application 030 when the I/O path used by the server001 is modified. When switching of the I/O path used by the server 001causes modification of the storage side port 024, the cache 021, and theRAID group 033 used by the application 030, the I/O loads on the storageside port 024, the cache 021, and the RAID group 033 which have beenused by the application are decreased. For this, the aforementioned caseis identical to the case when the logical volume 034 is moved to anotherstorage side port 0224, cache 021, and RAID group 033. Accordingly, byinputting a plurality of setting information in the setting informationinput view 301, it is possible to identify the application 030 whose I/Oamount may be increased by the I/O path modification and the resourceand the application 030 whose I/O performance may be lowered by the I/Oincrease of the application 030.

Furthermore, by applying the present embodiment, when reducing the I/Oload on the RAID group, it is possible to decide the logical volume tobe moved considering the range of affect of the I/O volume increase ofthe application 030 using the RAID group to another application 030.More specifically, the processes which will be explained below areexecuted for each of the logical volumes 034 contained in a particularRAID group 033.

Firstly, a logical volume 034 to be moved is specified in the resourceselection region 610 in the setting information input view shown in FIG.6. Next, the movement of the logical volume 034 is selected in theoperation list 621. Next, the storage performance analysis program 110executes the process explained in the example and displays the I/Operformance lowering storage resource display view 303 and the I/Operformance lowering application display view 304. Whereby, it ispossible to identify the resource and the application which are affectedby the movement of each logical volume 034 and accordingly, it ispossible to select the setting modification which will not affect aparticular application. Moreover, it is possible to select the settingmodification which minimizes the number of applications whose I/Operformance is affected. It should be noted that here, a list ofresources and applications which are affected is displayed. However, itis also possible to display the number of resources and the number ofapplications which are affected.

Furthermore, it is also possible to display the performance of eachresource corresponding to the resource name 801 on the I/O performancestorage resource display view 303 after the storage settingmodification. Moreover, it is also possible to display the performanceof each resource corresponding to the lowering condition 802. Thisenables check of the I/O amount increase from the application. Moreover,since the range affected by the storage setting modification isidentified, it is possible to immediately detect deterioration of theI/O performance caused by the storage setting modification. On the otherhand, in the conventional method, a user should manually specify therange of affect, which requires a certain time. This embodiment reducesthe labor required for detecting the problem.

By displaying the I/O amount increase application, the I/O performancelowering storage resource, and the I/O performance lowering applicationon the system configuration of FIG. 12 displayed on the display view, itis possible to rapidly grasp the range affected by the storage settingmodification. Furthermore, by displaying the resource affecting othersand the resource affected by the setting modification on the systemconfiguration shown in FIG. 12, it is possible to grasp the details ofaffect caused by the setting modification.

When a task system is formed by a plenty of applications andrelationship between some applications is known in advance, thisrelationship may be used to narrow the application candidates includedin the range affected by the setting modification.

It should be further understood by those skilled in the art thatalthough the foregoing description has been made on embodiments of theinvention, the invention is not limited thereto and various changes andmodifications may be made without departing from the spirit of theinvention and the scope of the appended claims.

1. A system comprising, at least one server; at least one storagesubsystem; and a storage management server connected to the at least onestorage subsystem and the at least one server via a network, the storagemanagement server comprising: a first collecting unit configured tocollect information on connection relationship between resources on anI/O path from each of applications in the at least one server to alogical volume used by the applications as configuration informationfrom the at least one server and the at least one storage subsystem; asecond collecting unit configured to collect performance information oneach of the resources on the I/O path from each of the applications inthe at least one server to the logical volume used by the applicationsfrom the at least one server and the at least one storage subsystem; arule table which includes IF-THEN type rules for avoiding performancedeterioration of each application, each of the rules storing a cause anda condition in a preamble part and storing a countermeasure in aconclusion part; an I/O amount increase application search engine forinputting a setting modification definition for balancing an I/O load ofthe at least one storage subsystem, specifying a resource on the I/Opath whose I/O load is reduced according to the setting modificationdefinition, and identifying a first application whose I/O amount may beincreased, the setting modification definition being configured toeliminate a predicted bottleneck that may occur between the at least oneserver and the at least one storage subsystem and defining movement ofthe logical volume; an I/O performance lowering resource search enginefor specifying a resource on a I/O path used by the first applicationwhose I/O amount may be increased based on the configurationinformation; and an I/O performance lowering application search enginefor identifying a second application using the resource specified by theI/O performance lowering resource search engine based on theconfiguration information, wherein the I/O performance loweringapplication search engine sets the specified I/O performance loweringresource as the cause of the rule and also sets the I/O amount increasedpath specified by the I/O performance lowering resource search engine asa condition of the rule for the second application, and obtains thecountermeasure as the conclusion from the rule, and displays a name ofapplication, the cause, the condition and the countermeasure on adisplay device.
 2. The system according to claim 1, wherein the I/O pathfrom each application in the at least one server to a logical volume inthe at least one storage subsystem includes at least one of server sideports and at least one of storage side ports.
 3. The system according toclaim 2, wherein the I/O amount increase application search engineidentifies the first application, if none of the utilization ratio ofthe server side ports and storage side ports on the I/O path from thefirst application to the logical volume used by the first applicationexceeds a predetermined value.
 4. The system according to claim 1,wherein the I/O performance lowering application search engine displaysthe name of the second application, the cause and the countermeasure ina table form on the display device.
 5. The system according to claim 2,wherein the rule stores, when the cause is the storage side portperformance deterioration and the condition is that the I/O amountincreased between the first application to the storage side port, thecountermeasure is that the second application is given a priority ofusing the storage side port.
 6. The system according to claim 2, whereinthe I/O path further includes a disk cache, wherein the rule stores,when the cause is a cache performance deterioration and the condition isthat the I/O amount increased between the second application to thestorage side port via the cache, the countermeasure is that the cache ofa logical volume is made resident.
 7. A storage management method for asystem having at least one server, at least one storage subsystem, and astorage management server comprising a rule table and connected to theat least one storage subsystem and the at least one server via anetwork, the method comprising: collecting information on connectionrelationship between resources on an I/O path from each of applicationsin the at least one server to a logical volume used by the applicationsas configuration information from the at least one server and the atleast one storage subsystem; collecting performance information on eachof the resources on the I/O path from each of the applications in the atleast one server to the logical volume used by the applications from theat least one server and the at least one storage subsystem; inputting asetting modification definition for balancing an I/O load of the atleast one storage subsystem, specifying a resource on the I/O path whoseI/O load is reduced according to the setting modification definition;identifying a first application whose I/O amount may be increased, thesetting modification definition being configured to eliminate apredicted bottleneck that may occur between the at least one server andthe at least one storage subsystem and defining movement of the logicalvolume; specifying a resource on a I/O path used by the firstapplication whose I/O amount may be increased based on the configurationinformation; identifying a second application using the resourcespecified based on the configuration information, wherein the rule tableincludes IF-THEN type rules for avoiding performance deterioration ofeach application, each of the rules storing a cause and a condition in apreamble part and storing a countermeasure in a conclusion part; settingthe specified I/O performance lowering resource as the cause of therule; setting the I/O amount increased path specified in the specifyinga resource step as a condition of the rule for the second application;obtaining the countermeasure as the conclusion from the rule; anddisplaying a name of application, the cause, the condition and thecountermeasure on a display device.
 8. The method according to claim 7,wherein the I/O path from each application in the at least one server toa logical volume in the at least one storage subsystem includes at leastone of server side ports and at least one of storage side ports.
 9. Themethod according to claim 8, further comprising: identifying the firstapplication, if none of the utilization ratio of the server side portsand storage side ports on the I/O path from the first application to thelogical volume used by the first application exceeds a predeterminedvalue.
 10. The method according to claim 7, further comprising:displaying the name of the second application, the cause and thecountermeasure in a table form on the display device.
 11. The methodaccording to claim 8, wherein the rule stores, when the cause is thestorage side port performance deterioration and the condition is thatthe I/O amount increased between the first application to the storageside port, the countermeasure is that the second application is given apriority of using the storage side port.
 12. The method according toclaim 8, wherein the I/O path further includes a disk cache, wherein therule stores, when the cause is a cache performance deterioration and thecondition is that the I/O amount increased between the secondapplication to the storage side port via the cache, the countermeasureis that the cache of a logical volume is made resident.
 13. A computerreadable storage medium storing a program for a storage managementmethod for a system having at least one server, at least one storagesubsystem, and a storage management server comprising a rule table andconnected to the at least one storage subsystem and the at least oneserver via a network, the method comprising: collecting information onconnection relationship between resources on an I/O path from each ofapplications in the at least one server to a logical volume used by theapplications as configuration information from the at least one serverand the at least one storage subsystem; collecting performanceinformation on each of the resources on the I/O path from each of theapplications in the at least one server to the logical volume used bythe applications from the at least one server and the at least onestorage subsystem; inputting a setting modification definition forbalancing an I/O load of the at least one storage subsystem, specifyinga resource on the I/O path whose I/O load is reduced according to thesetting modification definition; identifying a first application whoseI/O amount may be increased, the setting modification definition beingconfigured to eliminate a predicted bottleneck that may occur betweenthe at least one server and the at least one storage subsystem anddefining movement of the logical volume; specifying a resource on a I/Opath used by the first application whose I/O amount may be increasedbased on the configuration information; identifying a second applicationusing the resource specified based on the configuration information,wherein the rule table includes IF-THEN type rules for avoidingperformance deterioration of each application, each of the rules storinga cause and a condition in a preamble part and storing a countermeasurein a conclusion part; setting the specified I/O performance loweringresource as the cause of the rule; setting the I/O amount increased pathspecified in the specifying a resource step as a condition of the rulefor the second application; obtaining the countermeasure as theconclusion from the rule; and displaying a name of application, thecause, the condition and the countermeasure on a display device.